1. Field of the Invention
The present invention relates to an outboard motor, and in particular to a shift linkage mechanism for an outboard motor.
2. Description of Related Art
Outboard motors recently have become equipped with four-cycle engines. The use of four-cycle engine in the power head of the outboard motor, however, raises some formidable challenges in regard to the engine layout and arrangement within the protective engine cowling.
Prior four-cycle engines commonly include a large crankcase, and thus larger sizes, as compared with two-cycle engines. A larger engine also results because a four-cycle engine requires an oil pan. As a result, prior engine designs have struggled to provide sufficient space within the cowling in which to position many of the outboard motor components, including a shifting mechanism which controls a transmission of the outboard motor.
In prior four-cycle engine layouts, the shift linkage mechanism commonly lies to the side of the engine, near an air intake into an induction system of the engine. This location of the shifting mechanism and exposes the mechanism has resulted in an overly complicated mechanism. The increased number of parts and the complexity of the assembly may lead to assembly errors and to an increased possibility of malfunction.
In addition, the location of the shifting mechanism on the side of the engine tends to increase the size of the power head of the outboard motor. The power head generally extends above the transom of the watercraft and, as a result, the power head produces aerodynamic drag on the watercraft as the watercraft speeds over the water. The size and shape of the power head directly affect the amount of drag produced. The larger sized power head, which results from the prior layout of the shift actuation mechanism, thus negatively increases the drag experienced by the associated watercraft.